1. Field of the Invention
The present invention relates to a finger operable electronic control apparatus of the type including a finger actuator movable in plural directions, and which is particularly adapted for controlling functions such as the movement of a cursor on a display screen.
2. Description of the Prior Art
Heretofore, one common approach for controlling the movement of a cursor on a display screen requires four cursor control keys. Each of these keys is associated with moving the cursor on the screen at a constant speed in a respective up, down, left, or right direction. One such device is produced by Wang Laboratories, Inc. of Lowell, Mass., and designated as a word processing terminal model number 5536-A. With this approach, an operator either has to use four fingers for moving the cursor in the four directions or shift one finger from key to key to position the cursor. In addition, each of these keys is only capable of controlling one function inasmuch as each key is dedicated to moving the cursor at one speed in only one direction.
Another example of a cursor control apparatus comprises a joy stick or lever which projects upwardly from and is pivoted to a housing and which is shiftable in different directions to control the movement of an electronic cursor or other image on a screen. Movement of the stick in different directions opens and closes electrical contacts which are then used in generating electrical signals. These signals control the movement of the image on the screen.
Although such devices may be operated by using a single finger, for example, on top of the joy stick, satisfactory control is difficult to achieve. To overcome this, the joy stick is usually grasped by the user's hand. However, it is more difficult to move one's hand than to move one's finger. As a result, a user's wrist can tire from heavy use of a joy stick. Moreover, with this approach, a user's other fingers are unavailable for other purposes.
Also, there are a number of prior multiple position switch designs. In one basic type, a central pin or rod is pivotally supported for movement in several directions, a finger operable button is connected to the rod and used to move the rod. Electrical contacts are opened and closed in response to the position of the rod. Electrical control signals are generated in response to the opening and closing of the contacts. In addition to the rod being movable in several directions, the button frequently may be moved up and down relative to the rod to generate an additional electrical control signal. U.S. Pat. Nos. 3,828,148 of Roeser; 4,081,068 of Zap; 4,201,489 of Zap; 3,335,240 of Dhaens; and 2,532,228 of Hesh exemplify such devices. It should also be noted that none of these references are understood to illustrate the use of such a multi-position electrical switch for controlling the motion of a cursor on a display screen.
Still other explarary multi-position switches are disclosed in U.S. Pat. Nos. 4,029,915 of Ogima; 3,965,315 of Wuenn and 3,633,724 of Samuel. In Ogima, keys are mounted by a central spring to a base for movement by a user's finger in one of four directions. Movement of the key is used to generate control signals which are transmitted to a calculator circuit electrically connected to contacts operated by the key. The patents to Wuenn and Samuel each disclose finger actuated typewriter keys which are movable in plural directions for use in controlling the printing of characters by a typewriter. In Samuel, the keys are supported by a central pivot with springs being utilized to bias the keys to a neutral position. The keys of the Wuenn device are pivotally supported by a central bolt so as to permit movement of the key in multiple directions.
Although these prior devices exist, there is a need for an improved finger operated electronic control apparatus movable in plural directions for use in generating electrical control signals, such signals being used to control the movement of a cursor or other image on a display apparatus and for other purposes.